Tightly sealed carton blank



K. D. BIXLER TIGHTLY SEALED CARTON BLANK Dec. 29, 1964 Filed Jan. 14,1963 A m 4 0 MB CO Mi i MD. m L? J L f5 u n 9 m z a a 8 a n 1 a G n w MLa G. x, Z l m L *2 5 I w. k F a x. 5 F A H K FIG-.6.

United States Patent 3,163,347 THGHTLY SEALED CARTGN BLANK Kenneth D.Bixler, Huntington, N.Y., assignor to Diamond National Corporation, NewYork, N.Y., a corporation of Delaware Filed Jan. 14, 1963, Ser. No.251,258 6 (Ilaims. (Cl. 22939) This invention relates generally topaperboard cartons and more particularly to improvements in the end closureof a rectangular carton.

Cartons of the character involved are generally used for the purpose ofpackaging materials in which sifting and insect infestation areproblems, for example, packaging the soap powders, cereal, breakfastfoods, etc.

The primary object of the present invention is to provide a novel cartonwhich includes an improved end closure facilitating the assembly andsealing of the same.

A further object of the present invention is to provide a novel blankincorporating an improved end closure.

Still further objects of the present invention are to provide a novelend closure for a carton in which a plurality of interlocked closurepanels provide a pressure support to resist sealing pressure when anoverlying closure panel is adhesively secured thereon, insuring that theinterlocked closure panels are intimately engaged to permit adhesivesealing therebetween as well as providing a stable base for intimateadhesive securement of the overlying closure panel.

Another object of the present invention is to provide a novel carton inwhich the end closure includes locking tabs which aid in sealing thecarton and square the carton to afford an improved appearance.

And yet another objectof the present invention is to provide a novelmethod for assembling the end closure of a rectangular carton in whichthree interlocked closure panels provide a stable base to resistcompression during final sealing of the end closure.

And a still further object of the present invention is to provide anovel carton produced from a single, suitably scored and slit blank inwhich there is a minimum waste of material and in which the carton maybe erected on substantially standard equipment.

A further object of the present invention is to provide a flap interlockfor lock flaps of an end closure which causes the same to be retained inintimate positive contact for forming an adhesive seal therebetween tothus provide an adhesive sealing pressure in difficult sealing areas notafforded by prior art constructions.

Other objects and the nature and advantages of the instant inventionwill be apparent from the following description taken in conjunctionwith the accompanying drawings, wherein:

FIG. 1 is a fragmentary plan view of a carton blank incorporating thenovel features of the invention;

FIG. 2 is a fragmentary perspective view of the blank of FIG. 1,partially erected to form a rectangular tube, and showing the manner inwhich the first pair of closure panels are oriented during formation ofthe end closure of the carton, and illustrating diagrammatically how anadhesive coating may be applied to certain of the closure flaps of theend closure of the blank being assembled;

FIG. 3 is a view similar to FIG. 2, showing the next step of theformation of the end closure of the carton, illustrating how the panelsegments of the third closure panel are oriented before preforming thenext assembly step;

FIG. 4 is a view similar to FIGS. 2 and 3 showing the next step offorming the end closure in which the lock noses of the third closurepanel are inserted into cooperating apertures of a pair of underlyingclosure panels, and illustrating diagrammatically by means of 3,153,347Patented Dec. 29, 1964 ice arrows how a slight inward pressure may beapplied from opposite end walls of the tube;

PEG. Sis a vertical section taken substantially on the plane of line 55of FIG. 4 after the upper panel segment thereof has been oriented tosubstantially the phantom line position shown in FIG. 4;

FIG. 6 is a vertical section taken substantially on the plane of line 66of FIG. 5

FIG. 7 is a vertical section showing the position of the threeinterlocked closure panels, and showing by means of phantom lines theultimate position of the fourth closure panel in its relationship to apressure bar used to complete the final sealing of the end closure ofthe carton;

FIG. 8 is a fragmentary plan view of a modified embodiment of blank forforming the novel end closure; and

FIG. 9 is a fragmentary plan view of a still further modified embodimentof the novel end closure.

Referring to the drawings in detail, and first considering FIG. 1, aone-piece blank of substantially rectangular form is indicated generallyat 10. The blank 10 may be produced from any suitable paper board or thelike, and only the upper end portion thereof is disclosed in detail. Thelower portion of the blank may comprise a conventional end closure ormay comprise a duplication of that'shown in FIG. 1. For the purposes ofdescribing the invention, it is believed unnecessary to show the lowerportion of the blank in detail since such construction is believed to beclearly evident to those skilled in the art.

The blank 10 includes a pair of alternately disposed, mutually parallelside Wall panels 12 and 14 hingedly connected to a pair of alternatelydisposed end wall panels 16 and 18 by means of mutually parallel fold orscore lines 20, 22 and 24. The side Wall panel 12 includes a linear sidemargin 26 normal to a top margin 27 and the end wall panel 18 ishingedly connected by fold line 28 to a connector fiap 30.

The end margins of the panels 12-18 are defined by a transverse foldline 32 normal to the fold lines 20, 22, 24 and 28. Hingedly connectedat the fold line 32 is a first pair of rectangular closure panels orflaps 34 and 36 which are alternately disposed between a second pair ofclosure panels or flaps 38 and 40 which are hingedly connected at thefold line 32. The closure panels or flaps 3% may be reversed from theposition shown as is clearly evident to those skilled in the art.

The side edge margins of the panels 34-38 are defined iby intermediatecut lines 42, 44 and 46 which are in colinear relationship with therespective fold lines 20, 22 and 24. The end margin 48 of the closurepanel 38 is in colinear relationship with the margin 26 of the side wallpanel 12, and the end margin 50 of the closure panel 36 is in colinearrelationship with the fold line 28 for the connector panel 36.

The closure panel 38 includes an intermediate, transverse,.-fragmentaryfold line 52 parallel to the fold line 32 and defining in the closurepanel 38 elongated and upper or outer panel segment 54 and a lower orinner panel segment 56. The panel segments 54 have formed integral andcoplanar therewith by means of arcuate.

ing through the fold line 52 and which have a height X 7 which issubstantially equal to the maximum width of the lock tab 62 and 64 whichis also indicated at X.

3 The marginal edges 70 and 72 are respectively located a distance D andC from out line 42 and marginal edge 50, respectively, these distancebeing'the approximate distance between the fold line 32 and segmentalfold line 52.

The distances A and B indicate the inner or lowerrnost edge of theapertures 68 and 66, and the relationship of such distances areindicated at B and A with respect to the lock tab 62 and 64.

The aperture portions 66 and 68 are substantially closed by sealingflaps 74 and 76 hingedly connected at 78 and 80, respectively, to theclosure panels 34456.

The sealing flaps 74 and '76 may be reduced to provide a clearance 82and 84, respectively, approximately the same thickness as the caliper ofthe blank 16.

Referring to FIG. 8, the fragmentary portion of a slightly modifiedblank is indicated generally at 100 and portions thereof similar to thatof the previously described embodiment will be identified by similarreference oharacters and only the distinguishing structure will bedescribed in detail.

In this embodiment, the closure panel 134 has extending therethrough anaperture portion 166. This aperture portion 166 includes a margin 170in'the relationship previously described with respect to the'margin 70of the blank 10. .However, it will be noted that in this embodiment thesealing flaps, previously described, have been eliminated.

Referring to FIG. 9, a still further modified carton blank is indicatedgenerally at 200, and in this embodiment those portions functioningsimilar to those described with respect to FIG. 1, Will be identified bymeans of reference characters used to describe FIG. 1.

In the closure panel 38 of the blank 26%, the lock tabs 262 and 264 areformed by cut lines 258 and 260 originating from the fold line 52, andthe lock tabs 262 and 264 include thereon lock nose portions 265 and267, respectively. The width of the lock tabs 262 and 264 at thetransverse fold line 52 is indicated at X, i.e. is substantially thesame width as the previously described lock tabs 62 and 64.

The closure panel 234 has extending therethrough an aperture portion 266having a linear margin270 in the relationship described with respect tothe similar struc ture of FIG I. It will be noted that the height of thelinear margin 270 is substantially equal to t-he width X of the locktabs and thus when the carton is assembled a the lock nose portions 265will be slightly deformed or engage beyond the uppermost end of theaperture portion 266 at the margin 27%. The aperture portion 266includes a notched out portion 273 which facilitates the entry orbending over of the lock nose portion 265 of the lock tab 262 when theend closure of the carton is being formed.

Method of Assembly The carton body formed into a rectangular tube bydisposing the side wall panels 12 and 14, and the end wall panels 16 and18 in mutually parallel relationship and securing the connector panel3t} adjacent the marginal edge 26 in any suitable manner. The closurepanels 38 and 40 are folded outwardly as clearly seen in FIG.

2, and a layer of adhesive may be applied to the inner surfaces thereofby means of rollers R, and a suitable folding bar 86 is utilized to foldthe closure panels 34 and 36 inwardly and into substantially coplanarrelationship. I

When the closure panels 34 and 36 are folded inwardly, they will tend tounfold upwardly or outwardly of their coplanar relationship but areprevented from folding upwardly by the folding bar 36.

Referring toFIG. 3, suitable -folding bars 88, and 90 engage the closurepanel 38 and fold the panel segment 54 toward overlying relationshipwith respect to the panel segment 56. The sealing bar 88 will have arelatively sharp edge which will engage or come in contact with '96 willbe utilized to orient the closure panel segment 56 into substantiallyoverlying relationship with respect to the closure panels 34 and 36-,and the panel segment 54 will be disposed substantially vertical and thelock noses thereof, will be inserted behind the marginal edges 79 and 72of the closure panels 34- and 36, respectively. The panel segment 54will then be pivoted toward the phantom line position shown in FIG. 4,and as seen in FIGS. 5

and 6, will be ultimately disposed in the position shown insolid linesin FIG. '7.

As indicated by the direction arrows S in'FIGS. 4 and 5, pressure may beinitiated on the end walls 16 and 18, desired, to facilitate theinsertion of the lock tabs 62 and When the closure panels 34, 36 and 38,which includes segments 54 and 5'6, are interlocked as indicated in FIG.

7, these panels will tend to spring upwardly and outwardly as indicatedby the dotted direct-ion arrows in FIG. 7.

It will be noted that as the panel segment 54 is moved downwardly of theposition shown in FIG. 6 to that of FIG. 7; a lifting force indicated bythe direction arrow E will be applied to the undersurface of the closurepanels '34 and 36 inasmuch as the locking tabs 62 and 64 are disposed inthe plane of segment 54. This upward force aids in adhesively securingor gluing the panel 38 to panel 4%) at the edge 27 thereof. In normalgluing, sealing at the edge 27 of the panel 40 is generally a criticalarea.

The closure panel 40 will then be moved from the solid to the phantomline position shown in FIG. 7 by suitable forming bars, and pressed ontop of the closure panel 38 to be secured thereto by means of a suitableadhesive. The closure panels 38 and 49 may, for example, include on theinner surface thereof a heat responsive adhesive, and a pressure bar 99may be utilized to energize the heat-responsive adhesive, causing theinner surface of the panel .40 to adhere to the outer face of panel 38,the inner surface of the panel 38 adhering to outerfacc or surfaces ofthe panels 34 and 36.

Briefly in review, it will be noted that the blank from which thetightly sealed carton is. formed is substantially rectangular and thus aminimum or Waste or scrap results in the initial die cutting of theblank. The interlock provided by closure flaps 34, 36 and 38 provide apressureresisting support against which the closure flap 40 may be motesa better glue bond between flaps 34, 36 and 38,

thusrheiping to promote a better total seal when panel 40 is applied onthe upper surface of panel 38. All of the sealing panels or flaps 3440,are maintained in positive contact after adhesive application whichpermits sealing by preventing the surface tension of the adhesive to beruptured when pressure is applied exteriorly of the closure for the endof the carton being formed.

As will be evident to those skilled in the art, the assembly and closingof the novel closure will require a minimum of conversion from standardequipment conventionally 'used for this purpose. Although prior artclosures are generally utilized to resist an internal force whichattempts to open the carton, the end closure disclosed and describedabove, is in a sense the reverse of a positive closure. The primarypurpose of the interlocked closure panels 34, 36 and 38 is to affordresistance to downward external pressure, such as that applied by thecompression section of a sealing machine. Further, this stable base orresistance to compression duning final sealing, lends itself to use withheat activated, pro-applied adhesives which must be maintained underpressure for a predetermined interval after heat has been applied toactivate the adhesive. In order for the heat response of adhesive to beeffective, some pressure must be applied to the portions being securedtogether. In the prior art it was generally necessary to provide sometype of jig or pressure plate within a carton being heat sealed. The endclosure of the present invention, eliminates the necessity foradditional equipment since the closure panels 34-38 provide a stable andupwardly reacting base against which the closure panel 40 may besuitably pressed.

Additionally, the novel end closure lends itself to be squeezed duringfinal sealing in the manner indicated by the direction arrows S on FIG.5. When squeezing pressure is applied to the side panels 16 and 18, inaddition to the natural resiliency of the closure panels tending tospring upwardly, forces react on the lock tabs at the edges of theapertures of which they are shouldered, to provide an upward thrustforce tending to displace the panel segment 54 upwardly to accordinglyprovide a stable and upwardly resisting base against which pressurizedsealing force may be applied.

It will be obvious to those skilled in the art that various changes maybe made without departing from the scope of the invention and thereforethe invention is not limited to what is shown in the drawings anddescribed in the specification but only as indicated in the appendedclaims.

What is claimed is:

1. A carton blank forming a rectangular, glued end carton comprising aplanar body member including pairs of alternately disposed side and endwall panels hingedly connected on mutually parallel fold lines, atransverse fold line normal to said mutually parallel fold lines andbordering one end of said side and end wall panels, said body memberincluding pairs of alternately disposed closure panels hingedlyconnected at said transverse fold line and defined by cut-linescoinciding with certain of said mutually parallel fold lines at saidtransverse fold line for forming free side edges on said closure panels,one of said closure panels in alignment with one of said pairs side wallpanels including a fragmentary, transverse fold line extending to freeside edges thereof and parallel to said first mentioned transverse foldline and defining upper and lower panel segments therein, said upperpanel segment including a pair of integral lock tabs spaced along saidfragmentary fold line and defined by cut-lines originating at saidfragmentary fold line, each of said pair of closure panels in alignmentwith said end wall panels including aperture portions, said apertureportions having a height substantially equal to the Width of said locktabs for receiving the same therein when the carton is 7 closed, saidaperture portions including one marginal edge normal to a plane passingthrough said fragmentary fold line.

2. Carton blank as set forth in claim 1 in which said pair of closurepanels in alignment with said end wall panels include displaceableseal-flap elements hingedly connected thereto on fold lines oppositesaid one marginal edge. e

3. A blank as set forth in claim 1 in which said lock tabs each includea lock nose portion adjacent the juncture of said fragmentary fold lineand said cut-lines defining said lock tabs, said one marginal edge ofsaid aperture portions being substantially equal in length to the widthof said lock tabs and said fragmentary fold lines for deformablyreceiving said lock nose portions therethrongh.

4. In a rectangular, glued end carton formed from a single blank andincluding opposed parallel pairs of side and end walls disposed inrectangular relationship, the improvement comprising a first of pair ofinwardly folded closure panels hingedly respectively connected to saidend walls and disposed in spaced coplanar relationship, said pair ofinwardly folded closure panels each including an intermediate apertureportion having a marginal edge parallel to said side walls, a thirdclosure panel hingedly connected to one of said side walls at said oneend, said third closure panel including a transverse fold line forminginner and outer panel segments thereon, said outer panel segmentincluding coplanar, spaced lock tabs extending across said transversefold line and formed from said inner panel segment, said third closurepanel overlying said pair of inwardly folded closure panels with saidlock tabs each extending through one of said intermediate apertureportions and beneath and beyond said marginal edge towards said one sidewall panel for providing a relatively stable base with said firstmentioned pair of closure panels, and a fourth closure panel hingedlyconnected to said other side wall at said one end, and overlying saidthird closure panel and being adhesively secured thereto.

5. The structure of claim 4 in which said pair of inwardly foldedclosure panels include an end seal flap at said intermediate apertureportions sealingly engaging beneath said lock tabs.

6. The structure of claim 4 in which said intermediate aperture portionsand said lock tabs include interlocked lock notch and lock noseportions, respectively.

References Cited in the tile of this patent UNITED STATES PATENTS GreatBritain Nov, 11,

1. A CARTON BLANK FORMING A RECTANGULAR, GLUED END CARTON COMPRISING APLANAR BODY MEMBER INCLUDING PAIRS OF ALTERNATELY DISPOSED SIDE AND ENDWALL PANELS HINGEDLY CONNECTED ON MUTUALLY PARALLEL FOLD LINES, ATRANSVERSE FOLD LINE NORMAL TO SAID MUTUALLY PARALLEL FOLD LINES ANDBORDERING ONE END OF SAID SIDE AND END WALL PANELS, SAID BODY MEMBERINCLUDING PAIRS OF ALTERNATELY DISPOSED CLOSURE PANELS HINGEDLYCONNECTED AT SAID TRANSVERSE FOLD LINE AND DEFINED BY CUT-LINESCOINCIDING WITH CERTAIN OF SAID MUTUALLY PARALLEL FOLD LINES AT SAIDTRANSVERSE FOLD LINE FOR FORMING FREE SIDE EDGES ON SAID CLOSURE PANELS,ONE OF SAID CLOSURE PANELS IN ALIGNMENT WITH ONE OF SAID PAIRS SIDE WALLPANELS INCLUDING A FRAGMENTARY, TRANSVERSE FOLD LINE EXTENDING TO FREESIDE EDGES THEREOF AND PARALLEL TO SAID FIRST MENTIONED TRANSVERSE FOLDLINE AND DEFINING UPPER AND LOWER PANEL SEGMENTS THEREIN, SAID UPPERPANEL SEGMENT INCLUDING A PAIR OF INTEGRAL LOCK TABS SPACED ALONG SAIDFRAGMENTARY FOLD LINE AND DEFINED BY CUT-LINES ORIGINATING AT SAIDFRAGMENTARY FOLD LINE, EACH OF SAID PAIR OF CLOSURE PANELS IN ALIGNMENTWITH SAID END WALL PANELS INCLUDING APERTURE PORTIONS, SAID APERTUREPORTIONS HAVING A HEIGHT SUBSTANTIALLY EQUAL TO THE WIDTH OF SAID LOCKTABS FOR RECEIVING THE SAME THEREIN WHEN THE CARTON IS CLOSED, SAIDAPERTURE PORTIONS INCLUDING ONE MARGINAL EDGE NORMAL TO A PLANE PASSINGTHROUGH SAID FRAGMENTARY FOLD LINE.